—What do you think of the report about the air pollution on TV last night?—I think the situation is so that we should take action to protect the environment.
—I knocked into a tree when I went to the bus stop for my friend.—I suppose you _____too fast.
this key is your mother’s.
You don’t know ______ I want to see you again. It’s a year since I last saw you.
---Where’s Li Hua?---Look! He _______ tennis on the playground.
With the help of the new technology, you __ e-mail your friends by mobile phone.